Resonant Charge Pump Frequency Control for Overvoltage Protection
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Solution Overview
Problem
Resonant switched-capacitor converters generate excessively large output voltages when input voltages are high, leading to potential damage to electronic devices due to a fixed conversion ratio.
Innovation Solution
A power converter with switches, a flying capacitor, and an inductor, controlled by a circuit that switches at resonant and regulated frequencies based on input voltage thresholds to prevent overvoltage, using a control circuit to manage the switches and form a resonant circuit with the flying capacitor and inductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the resonant switched-capacitor converter uses a fixed conversion ratio, then the power conversion efficiency is improved and power consumption during power transfer is reduced, but the output voltage becomes excessively large when input voltage is high, causing damage to electronic devices
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed conversion ratio to a dynamic, adjustable conversion ratio. The control circuit monitors input voltage levels and dynamically adjusts the switching frequency and duty cycle of the resonant switched-capacitor converter. When input voltage exceeds a threshold, the system switches from resonant frequency operation to a regulated frequency mode, thereby dynamically adapting the conversion ratio to prevent overvoltage while maintaining efficiency during normal operation.
Solution Approach 2:
The patent implements parameter changes by modifying the switching frequency and duty cycle based on input voltage conditions. The system operates at resonant frequency for normal conditions to maximize efficiency, but transitions to a regulated frequency exceeding the resonant frequency when input voltage is high. This parameter adjustment changes the effective conversion ratio, preventing excessive output voltage while maintaining low power consumption during normal operation.
2Productivity
If the converter operates at resonant frequency for all input voltages, then the system efficiency is maximized, but the output voltage cannot be regulated when input voltage exceeds the threshold
Solution Approach 1:
The system employs dynamic operation mode switching based on input voltage levels. During normal operation below the voltage threshold, the converter operates at resonant frequency for maximum efficiency. When input voltage exceeds the threshold, the control circuit dynamically transitions the system to a regulated frequency mode, adjusting the switching parameters to maintain safe output voltage levels. This dynamic adaptation ensures both high efficiency during normal operation and reliable overvoltage protection when needed.
Solution Approach 2:
The patent implements feedback control by monitoring the input voltage level and using this information to adjust the switching frequency and duty cycle. The control circuit receives feedback about input voltage conditions and automatically transitions between resonant and regulated operation modes. This feedback mechanism ensures the system maintains optimal efficiency during normal operation while automatically activating voltage regulation when input voltage becomes excessively high, thereby protecting the load.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents overvoltage damage by regulating output voltage to a safe level, enhancing system efficiency and protecting the load.
Implementation Method 1
If the flying capacitor is coupled to the inductor, the flying capacitor and the inductor form a resonant circuit having the resonant frequency
Data Source
AI summary
A power converter includes first to fourth switches, a flying capacitor, an inductor, an output capacitor and a control circuit. The first to fourth switches are sequentially coupled in cascode. The first switch is used to receive an input voltage. The flying capacitor is coupled across the second switch and the third switch, the inductor is coupled to the second switch, the third switch and the output capacitor. The output capacitor is used to output an output voltage. When the input voltage is less than an input voltage threshold, the control circuit is used to switch the first to fourth switches according to a resonant frequency. When the input voltage exceeds the input voltage threshold, the control circuit switch is used to the first to fourth switches according to a regulated frequency exceeding the resonant frequency.